1. Field of the Invention
The invention relates to a wireless bar code scanner which transmits bar code data to a personal computer. In particular, the invention relates to a wireless bar code scanner which transmits raw bar code data to a personal computer.
2. Description of the Related Art
Bar codes are used in a wide variety of applications for retrieving information from objects, such as price. In this respect, bar code scanners are of widespread use in grocery stores and department stores, for both inventory control and for point-of-sales transactions.
A bar code normally includes several bar code characters. A bar code character is a group of lines (bars) and spacings that represent a single number or letter. A bar code symbol is a collection of several bar code characters which represent an identification of a particular object. The lines of the bar code can vary in a range, for example, from about 1/8" to 1" in height, and from about 1 to 50 mils in thickness. The spacings between the lines making up the bar code may be of various widths, with the variations in the spacing being one determination of the type of bar code characters making up the bar code.
Typically, bar codes are read by illuminating the bars and spacings in a sequential manner, with the bars absorbing light and the background spacings reflecting light. This results in a pattern of reflections and nonreflections that is sensed by a light detecting circuit resident in the bar code scanner. The light detecting circuit provides an input to a digital processor, which interprets the bar code into a digital word.
The ability of a bar code scanner to read a bar code satisfactorily is dependent on its resolution. This resolution defines the ability of the bar code scanner to read the narrowest bar or space. Resolution is dependent on the size and sharpness of the spot of light that illuminates the bar code.
Once a bar code has been read by the scanner, the raw data obtained from the reflected light off of the bar code symbol is processed by circuitry inside the bar code scanner. The raw data may be subject to a first and/or second differential circuit, which causes the bar/space transitions to be more clearly set out in the raw bar code data. Additionally, the raw data is usually subject to amplification, as well as to being decoded by a decoder in order to obtain a digital representation of the bar code symbol.
Conventional systems also allow for a bar code symbol to be scanned by a bar code scanner to provide scanned data, wherein the scanned data is sent to another device for processing of the data. For example, U.S. Pat. No. 5,307,297, entitled "Data Processor With Wireless Auxiliary Input Apparatus", issued to S. Iguchi et al., discloses a data processor which has a receiver for receiving wireless signals on an external side wall of the data processor. Wireless signals are received from various devices, including a bar code scanner. U.S. Pat. No. 5,142,128, entitled "Oilfield Equipment Identification Apparatus", issued to G. Perkin et al., discloses an apparatus for identifying oil field equipment. A portable encapsulated passive circuit capable of transmitting an identification code is affixed to a piece of oil field equipment, and the circuit is activated by a reader, which receives and decodes the identification code and transmits it to a central computer.
U.S. Pat. No. 4,916,441, entitled "Portable Handheld Terminal", issued to P. Gombrich, discloses a network system used in a patient health care system. A bar code reader is used in the network, and an RF modem is provided for wireless transmission of information from the bar code reader to devices on the network.
U.S. Pat. No. 5,414,624, entitled "Automatic Vehicle Parking System", issued to R. Anthonyson, discloses an automated vehicle parking system. A sensor is used in the system, and it sends data to a personal computer via wireless means. The sensor is able to identify a vehicle based on its vehicle identification number.
U.S. Pat. No. 5,426,423, entitled "Process and Device for Registering and Checking Items", issued to P. Raimbault et al., discloses a bar code reader which reads a bar code, and which transfers the read bar code by a frequency signal to computer elements.
U.S. Pat. No. 5,434,401, entitled "Signal Coupler", issued to P. Bauser, discloses communications between a photovoltaic generator and a microcontroller via the infrared spectrum, ultra violet spectrum or visible light.
The above-mentioned patents are each incorporated herein by reference.
In each of the above-mentioned conventional devices, once the data is sent via wireless means to another location, the other location performs processing on that data in order to determine the data corresponding to the scanned object. However, in accordance with the invention, other types of uses of the raw data at the other location may be achieved.